The primary objectives are: a) to assess the safety and tolerability, and to establish the maximum tolerated dose of CGP 57148B when administered orally to Ph chromosome positive CML patients in chronic-phase who are resistant to interferon-alpha, and b) to obtain pharmacokinetic profiles at different escalating doses. The secondary objectives are: a) to obtain preliminary evidence of anti-leukemic activity as shown by a decrease in peripheral white blood cell counts and the peripheral white blood cell counts and the percentage of Ph chromosome positive cells in the bone marrow, and b) to obtain preliminary evidence of inhibition of the tyrosine kinase activity of the chimeric Bcr-Abl protein using a phosphotyrosine immunoblot assay.